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Power system ultra-low frequency oscillation risk assessment method by considering multiple speed regulator dead zones

A power system and risk assessment technology, applied in the direction of reducing/preventing power oscillations, etc., can solve problems such as the inability to analyze frequency oscillations of multi-machine systems

Active Publication Date: 2020-02-21
STATE GRID SICHUAN ELECTRIC POWER CORP ELECTRIC POWER RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003]The purpose of this invention is to provide a method for assessing the risk of ultra-low frequency oscillations in power systems that takes into account the dead zones of multiple governors, so as to solve the problem that cannot be analyzed in the prior art including different dead zones. The frequency oscillation problem of the multi-machine system in the multi-machine system, to achieve the purpose of evaluating the ultra-low frequency oscillation risk of the power system with multiple governor dead zone links and different dead zone sizes

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  • Power system ultra-low frequency oscillation risk assessment method by considering multiple speed regulator dead zones
  • Power system ultra-low frequency oscillation risk assessment method by considering multiple speed regulator dead zones
  • Power system ultra-low frequency oscillation risk assessment method by considering multiple speed regulator dead zones

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Embodiment 1

[0036] A risk assessment method for ultra-low frequency oscillations in power systems considering the dead zone of multiple governors,

[0037] Including the following steps:

[0038] S1. Collect models and operating parameters of networked generators and their governors;

[0039] S2. Determine the transfer function G of the equivalent generator according to the moment of inertia, damping coefficient and load frequency adjustment effect of the generator gen , according to the governor model to determine the transfer function G of the linear part of each governor govi , using the description function method to calculate the description function NL of the dead zone link of each governor i ;

[0040] S3. Combining each governor G govi NL i , calculate the magnitude of its extended description function |G ei |sum phase angle ∠G ei , adding multiple extended description functions to form the extended description function G of the system e ;

[0041] S4. Utilize the extende...

Embodiment 2

[0058] The power system structure model provided by this embodiment is as follows figure 2 shown in figure 2 In the above, the network structure is ignored, and the generator set is composed of the most commonly used hydroelectric unit (hydraulic turbine + governor) and thermal power unit (steam turbine + governor), and the generator is an equivalent generator. Among them, the turbine G ht and its governor model G hgov They are:

[0059]

[0060] In the formula, T W is the time constant of water hammer effect, K D 、K P 、K I Respectively, the differential, proportional and integral coefficients of the governor, B P is the adjustment coefficient, T G is the time constant of the servo system.

[0061] The models of the steam turbine and its governor are:

[0062]

[0063] In the formula, F HP Proportion of the power generated for the high-pressure cylinder in the total turbine power, T RH is the reheat time constant, T CH is the main intake volume and chamber...

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Abstract

The invention discloses a power system ultra-low frequency oscillation risk assessment method by considering multiple speed regulator dead zones. The method comprises the steps of: collecting a networked generator and a speed regulator model and operation parameters thereof; determining a transfer function of an equivalent generator, determining a transfer function of each speed regulator linear part according to the speed regulator model, and calculating a description function of each speed regulator dead zone link; calculating the amplitude and the phase angle of each speed regulator extension description function in combination with each speed regulator and the dead zone link thereof, and adding and combining a plurality of extension description functions to form the extension description function of the system; establishing a unified frequency model; and on the basis of the unified frequency model, calculating the critical amplitude of the ultra-low frequency oscillation, so that the risk of the ultra-low frequency oscillation of the power system is evaluated. The method is used for solving the problem that in the prior art, frequency oscillation of a multi-machine system containing different dead zones cannot be analyzed, and the purpose of evaluating the ultralow-frequency oscillation risk of an electric power system which contains a plurality of speed regulator dead zonelinks and has different dead zone sizes is achieved.

Description

technical field [0001] The invention relates to the field of ultra-low frequency oscillation of electric power systems, in particular to a risk assessment method for ultra-low frequency oscillation of electric power systems taking into account the dead zone of multiple governors. Background technique [0002] Ultra-low frequency oscillation of power system is one of the most concerned frequency stability problems in recent years. The influence of the dead zone of the governor on the frequency oscillation cannot be ignored. The dead zone of the governor exists widely in the actual power grid and is different from each other. However, the current research method can only analyze a single dead zone link, and has not yet been able to analyze different dead zones. A Method for Frequency Oscillation of Multimachine Systems. Contents of the invention [0003] The purpose of the present invention is to provide a method for assessing the risk of ultra-low frequency oscillations in...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02J3/24
CPCH02J3/24
Inventor 范成围陈刚史华勃刘畅滕予非
Owner STATE GRID SICHUAN ELECTRIC POWER CORP ELECTRIC POWER RES INST